摘要 |
The invention is concerned with a new process for the preparation of compounds of formula wherein R is hydrogen, lower alkyl, lower alkoxy, cycloalkyl, cycloalkenyl, cycloalkyl-lower alkyl, lower alkenyl, lower alkynyl, aryl, aryl-lower alkyl, heterocyclyl or heterocyclyl-lower alkyl; the lower alkyl, cycloalkyl, lower alkenyl, cycloalkenyl, lower alkynyl, aryl-lower alkyl, aryl and the heterocyclyl moieties being unsubstituted or substituted with at least one group selected from carboxy, amino, carbamoyl, nitro, cyano, lower alkyl, lower alkoxy, hydroxy, halogen, aminomethyl, mercapto, trifluoromethyl and trichloroethyl. The compounds prepared according to above mentioned process are useful in the preparation of cephem, isoxacephem and carbacephem derivatives.
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